Lubricant seal

ABSTRACT

A unitized, hand installable lubricant seal for sealing between a bore and a shaft subject to rotation relative to each other, such as a vehicle wheel hub and axle, provides a resilient surface for sealingly engaging the bore, a resilient surface for sealingly engaging the shaft and a resilient seal lip to rigid wear surface running seal between the resilient surfaces. No special tools are required to install or remove the seal.

BACKGROUND OF THE INVENTION

Prior art seals for sealing between a bore and a shaft subject torotation relative to each other have often consisted of two or morecomponents which must be shipped separately, installed separately andcarefully oriented with respect to each other and/or have required aspecial tool to enable achievement of a metal to metal seal between arigid seal component and either the bore or the shaft.

In specific reference to lubricant seals for vehicle wheels the need topound a seal component into sealing engagement with either a bore in thewheel hub or with a peripheral surface on the axle often requires aspecial tool, is time consuming and, in some instances, damaging to thesealing surface of either the seal or the wheel hub or axle. Suchsurfaces and adjacent components, such as bearings, are also subject todamage upon removal of the seal.

SUMMARY OF THE INVENTION

This invention relates to an improved lubricant seal for sealing betweena bore and a shaft. The seal is hand installable and self-aligning andis a preassembled or unitized seal which can be shipped, stored andinstalled as a completed assembly.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a typical vehicle wheel hub and axleassembly having a lubricant seal of this invention;

FIG. 2 is a front view of the lubricant seal of this invention;

FIG. 3 is a partially sectioned side view of the lubricant seal of FIG.2;

FIG. 4 shows the cross-sectional configuration of the bore engagingcomponent of this invention;

FIG. 5 shows the cross-sectional configuration of the shaft engagingcomponent of this invention;

FIG. 6 is a partial view of a sectioned wheel hub, axle and lubricantseal of this invention and shows how the components of the lubricantseal coact with each other and with the hub and axle;

FIG. 7 is a partial front view of the bore engaging component shown inFIG. 4; and

FIG. 8 is a partial perspective view of the component shown in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a typical vehicle wheel hub and axle assembly 2 which iscomprised of an axle 3, an axle shoulder 4 and a spindle 5. A wheel hub6 which is substantially cylindrical in shape is mounted concentric tospindle 5 and adapted for rotation with respect to spindle 5 by frictionreducing means such as tapered roller bearing assembly 7 and bearingmeans 8, shown by convention only. Axle shoulder 4 and spacer means 9and threaded nut 10 on a threaded end 11 of spindle 5 maintain hub 6 ina desired axial position on spindle 5.

To reduce friction and prolong bearing life the bearings must belubricated. To lubricate the bearings it is common practice to maintaina desirable amount of a lubricant, such as oil, within chamber 12 of thehub 6 and closure means are provided at each end 13 and 14 of hub 6 tomaintain the lubricant within the assembly and prevent undesirablefluids and particulate matter from contaminating the lubricant.

Conventional hub caps well known to those skilled in the art of vehicledesign or vehicle manufacture or maintenance generally serve as aclosure means 15, shown in phantom lines, at end 13 of hub 6.

At end 14 of hub 6 the closure means must seal between the hub 6 and theaxle 3 and maintain a fluid seal both when hub 6 is rotating withrespect to axle 3 and when there is no rotative motion between the huband axle.

A bore 16 within hub 6 is concentric with and radially outwardly spacedfrom axle 3 and a seal means, such as seal 17 of this invention, isdisposed to sealingly engage bore 16 and a continuous annular portion ofthe peripheral surface 18 of axle 3 to prevent fluid flow betweensurface 18 and bore 16.

Referring to FIG. 2 lubricant seal 17 is annular in shape and has aradially outwardly facing surface 19 for sealingly engaging a radiallyinwardly facing surface of a bore and a radially inwardly facing surface20 for sealingly engaging a radially outwardly facing surface of an axleor shaft.

FIG. 3 shows a side view of seal 17 of FIG. 2 in which the upper frontquadrant of the seal has been cut away as indicated by appropriatesection lines in FIG. 2. Seal 17 is comprised of a resilient boreengaging member 21 and a resilient axle or shaft engaging member 22. Anannular rigid support member 23 provides support and structuralintegrity for member 21 and an annular rigid support and wear surfacemember 24 provides support for resilient member 22. Bore engagingsurface 19 is on resilient member 21 and axle or shaft engaging surface20 is on member 22.

Resilient members 21 and 22 are preferably formed of an elastomericmaterial which is durable, resilient and oil resistant. Nitrilesynthetic rubber compounds, such as Buna-N, work well. Also, materialssuch as fluoroelastomers, polyacrylates and silicones may be used. Rigidmembers 23 and 24 are preferably formed of steel.

FIG. 4 shows an enlarged cross section of annular resilient member 21and rigid support member 23. Member 21 is comprised of a substantiallycylindrical outer band 25 having a radially outwardly facing surface 19,a radially inwardly facing surface 26, which is concentric with andradially inwardly spaced from surface 19, and a first or wheel facingside 27 and a second or vehicle facing side 28. An integral assemblymaintenance lip 29 projects radially inwardly from side 27 substantiallyperpendicular to surface 26. An abutment projection 30 integral withband 25 and lip 29 extends axially outwardly from side 27.

An integral connective side web 31 extends radially inwardly from side28 of band 25 and is connected to an integral seal band 32. Side web 31has a first or wheel facing side surface 33 and a second or vehiclefacing side surface which is a radially oriented extension of side 28 ofcylindrical band 25.

Integral seal band 32 projects radially inwardly from side web 31 andhas as its radially innermost surface a lubricant seal lip 34. Aradially outermost surface 35 of seal band 32 extends axially from afirst or wheel facing side surface 33 of side web 31. Surface 35 issubstantially perpendicular to surface 33. Surface 35 is radiallyoutwardly facing, coaxial with and radially inwardly spaced from surface26 of band 25. A biasing means retention means, such as garter springgroove 36, is provided in surface 35. Garter spring groove 36 is coaxialwith and radially outwardly spaced from seal lip 34.

A spacer means, such as integral spacer tab 37 projects axiallyoutwardly from side 28 of side web 31 and an integral auxiliary orcontaminant seal lip 38 also extends axially outwardly from side surface28 of side web 31. Spacer tabs 37 are preferably arranged in a circularpattern coaxial with and radially inwardly spaced from surface 19 ofband 25, as best shown in FIG. 7.

FIG. 8 shows in perspective one of the spacer tabs 37 shown in FIG. 7.The tabs 37 are preferably formed integral with member 25. Each tab iscomprised of a main body portion 104 and a wear surface contactingportion 105 having end 100 which actually contacts wear surface 67 ofrigid member 24. The main body portion 104 provides strength and thecylindrical wear tip or button 105 provides a reduced surface area toprovide a reduction in friction between end 100 and a wear surface 67,such as shown in FIGS. 5 and 6.

Referring again to FIG. 4 a frusto-conical shaped assembly ramp 39 isformed between lubricant seal lip 34 and auxiliary seal lip 38.

Annular rigid support member 23 is comprised of a cylindrical bandportion 40 having a radially outwardly facing outer surface 41 and afirst or wheel facing side 42 and a second or vehicle facing side 43. Anintegral rigid side band 44 projects radially inwardly from side 43 ofband 41 and is oriented substantially perpendicularly to band 41. Rigidside band 44 has a vehicle facing side surface 45 which is disposedadjacent surface 33 of side web 31 for supporting side web 31 againstaxial movement, such as when an axial force directed toward member 23 isimposed on spacer tab 37.

A series of continuous annular sealing ridges 46 are preferably formedintegral with surface 19 and project radially outwardly from surface 19.

Resilient member 21 and rigid member 23 are formed separately and thenassembled as shown in FIG. 4. As member 21 is resilient it is forcedover rigid member 23 until assembly maintenance projection 29 clearsside 42 of band 40 and, due to the memory of the resilient material,moves radially inwardly to engage side 42 and maintain rigid member 23within member 21.

Cylindrical band portion 40 of rigid member 23 prevents radially inwardmovement of band 25 and integral rigid side band 44 supports resilientside web 31 against axial movement and thus aids in maintaining spacertabs 37 and auxiliary seal lip 38 in a desired position.

FIG. 5 shows an enlarged cross section of annular resilient member 22and rigid support and wear surface member 24.

Axle or shaft engaging resilient member 22 is comprised of a cylindricalband portion 50 having a first or wheel facing side 51, a second orvehicle facing side 52, a radially inwardly facing surface 20 and,concentric with and radially outwardly spaced from surface 20, aradially outwardly facing surface 53.

An assembly maintenance rim 54 extends radially outwardly from side 51of band 50. Rim 54 is substantially perpendicular to surface 53 of band50 and has an axial projection 55 which extends axially to overlap oroverhang a portion of surface 53 for forming a first rigid memberretention groove 56.

A resilient side member 57 is formed integral with and extends radiallyoutwardly from side 52 of band 50. Side member 57 is substantiallyperpendicular to surface 53 of band 50. Side member 57 has a first orwheel facing side surface 58 and a second or vehicle facing side surfacewhich is an extension of side 52 of band 50. An assembly maintenanceprojection 59 is formed integral with a peripheral or radially outermostportion of surface 58 and projects radially inwardly to overlap oroverhang a portion of surface 58 for forming a second rigid memberretention groove 60.

Rigid support and wear surface member 24 is comprised of a cylindricalband portion 61 having a first or wheel facing side 62, a second orvehicle facing side 63, a radially inwardly facing surface 64 and aradially outwardly facing wear surface 65.

An anchor recess, such as right angle groove 102, is preferably formedintegral with second side 63 of cylindrical band portion 61. Groove 102is comprised of leg 115 which extends radially outwardly from side 63and leg 116 which is integral with and extends axially from a radiallyoutermost portion 117 of leg 115.

An integral rigid side member 66 projects radially outwardly from leg116 of groove or recess 102. Side member 66 has a first or wheel facingaxially facing wear surface 67, a second or vehicle facing axiallyfacing surface 68, a friction reducing and stiffening groove 103 and aterminal peripheral portion 69.

Resilient member 22 and rigid member 24 are formed separately andassembled in the relationship shown in FIG. 5 by placing side 62 ofrigid band 61 into retention groove 56 and placing peripheral portion 69of side member 66 in retention groove 60, thus causing annular resilientmember 22 to be locked about annular rigid member 24. The anchor recess102 engages a complementary shoulder 130 on resilient member 22 and thusserves to prevent member 22 from sliding axially or radially relative tomember 24. Radially outwardly facing resilient surface 53 and radiallyinwardly facing rigid surface 64 are in sealing engagement with eachother for preventing fluid flow between surfaces 53 and 64.Additionally, band portion 61 of rigid member 24 limits radial outwardmovement of band portion 50 of resilient member 22 and rigid side member66 provides axial support for resilient side member 57.

FIG. 6 shows in an enlarged cross sectional view how members 21, 22, 23and 24 coact with each other when assembled to form seal 17, which isplaced in service between the bore 14 of wheel hub 6 and the peripheralsurface 18 of axle 3.

A typical conventional bearing assembly 7 comprising a bearing cup 70,bearing rollers, such as tapered roller 71, and bearing cone 72 isinterposed between spindle 5 and hub 6.

Resilient radially outwardly facing surface 19 of member 22 is sealinglyengaged with the radially inwardly facing surface of bore 14.

Lubricant seal lip 34 encircles and is in sealing engagement with wearsurface 65 of rigid member 24 and contaminant seal lip 38 is sealinglyengaged with a continuous annular portion of wear surface 67 of rigidmember 24.

A biasing means, such as garter spring 80, is retained within retentiongroove 36 to radially inwardly urge lubricant seal lip 34 intocontinuous engagement with wear surface 65 for aiding in preventingfluid flow between lip 34 and surface 65.

Resilient radially inwardly facing surface 20 of member 22 is sealinglyengaged with the peripheral surface 18 of axle 3 for preventing fluidflow between member 22 and axle 3.

Preferably, seal ridges 90 and 91 extend radially inwardly to comprisesurface 20 and effect a seal, as shown. Each seal ridge 90 and 91 servesto provide a continuous annular substantially dense or concentratedresilient sealing pressure against surface 18 and therefore each ridgereadily conforms to any surface irregularities which may be present onthe external surface of an axle.

In the same manner, resilient sealing ridges 46 on surface 19 ofresilient member 21 also serve to readily conform to any surfaceirregularities present on the surface of bore 14.

To assemble the preassembled or unitized seal 17 shown in FIGS. 2 and 3members 21 and 23 are assembled into the relationship shown in FIG. 4and members 22 and 24 are assembled into the relationship shown in FIG.5 to form two subassemblies. The garter spring 80 may be placed inretention groove 36 at this time. Annular assembly ramp 39 of member 21is then placed adjacent assembly maintenance rim 54 of member 22 and thetwo subassemblies are forced axially toward each other causing resilientseal band 32 to spread radially outwardly and be forced over rim 54. Theinherent elasticity of resilient seal band causes the seal band toretract radially inwardly once it has cleared rim 54 and lubricant seallip 34 encircles and engages surface 65 of member 24.

Annular garter spring 80 in retention groove 36, as shown in FIGS. 3 or6, urges the seal band radially inwardly and aides in assuring that thecomponents remain mutually entrapped. Seal 17, so assembled, is shippedand installed in the preassembled or unitized form, as shown in FIGS. 2or 3.

To effect installation of seal 17 the hub 6, referring to FIG. 6, isremoved from spindle 5 and seal 17 is forced axially into the bore 14 sothe seal ridges 46 sealingly engage the surface of bore 14. Seal 17 isforced axially inwardly, preferably by hand, until abutment projection30 rests against an appropriate locating surface, such as a portion ofbearing cup 70.

Hub 6 is then replaced on spindle 5 and forced, preferably manually,axially toward the axle 3 until properly seated. Upon forcing hub 6toward its proper seat on spindle 5 frusto-conical surface 120 pilotsmember 24 over the axle and ridges 90 and 91 sealingly engage surface 18of the axle.

As member 24 is forced over the axle its resistance to axial movementforces rigid wear surface 67 into engagement with an end 100 of eachspacer tab 37. Spacer tabs 37 then assure proper alignment of members 21and 24.

As shown in FIG. 4, auxiliary seal lip 38 extends axially outward beyondthe ends 100 of spacer tab 37. When seal 17 is installed the auxiliaryseal lip 38 is then inherently biased into sealing engagement with wearsurface 67.

Upon installation the ends 100 of spacer tabs 37 are engaged with aportion of surface 67 on each side of groove 103 but after an initialwear in period of rotational movement of the member 21 relative to rigidmember 24 the ends of the tabs are worn down sufficiently so that theyno longer have any substantial contact with surface 67. Groove 103serves to stiffen portion 66 of member 24 and also, due to reduction ofsurface engagement with end 100 of each spacer tab, it reduces thefrictional engagement between the spacer tabs and surface 67 to reducefrictional heat under dynamic conditions.

Auxiliary or contaminant seal lip 38 is self cleaning in the applicationshown in FIG. 6 as when it rotates it tends to impel contaminants whichcontact it radially outwardly by centrifugal force.

Notwithstanding the fact that in the applications shown herein the boreengaging components, member 21 and, of course, member 23, rotate uponvehicle movement and the axle or shaft engaging component, member 22,and, of course, member 24, remain fixed it will be readily understood bythose skilled in the art that the fluid seal of this invention as taughtherein will be useful for other applications where the axle or shaftrotates and the bore is fixed, i.e. not subject to rotation under normalcircumstances.

Additionally, it will be readily appreciated by those skilled in the artthat seals of this invention as taught herein may be used on the drivewheels of vehicles. In such applications the resilient radially inwardlyfacing surface of the axle engaging member would sealingly engage theaxle housing.

What is claimed is:
 1. In a fluid seal for sealing between a bore and ashaft, said seal having a first resilient member for engaging said bore,a second resilient member for engaging said shaft and a rigid wear andsupport member interposed between and sealingly engaged with at least acontinuous annular portion of each of said resilient members, said rigidmember having a cylindrical portion affixed to one of said first andsecond resilient members and a radially extending portion, said radiallyextending portion having a substantially annular portion of an axialside surface disposed for engaging an axial side of said other of saidresilient members for assuring proper alignment of said one of saidresilient members and said rigid member relative to said other of saidresilient members upon installation of said seal, the improvementcomprising:a continuous substantially annular stiffening groovecomprising a continuous annular surface deformation formed in saidsubstantially annular portion of said axial side surface of saidradially extending portion of said rigid member disposed for engaging anaxial side of said other of said resilient members, said stiffeninggroove being coaxial with and radially spaced from said cylindricalportion of said rigid member for aiding in preventing deformation ofsaid radially extending portion of said rigid member due to axial forceimposed upon said radially extending portion by said other of saidresilient members; and spacer means integral with said axial side ofsaid other of said resilient members, said spacer means being interposedbetween said axial side of said other of said resilient members and saidstiffening groove, said spacer means having a flat end portion alignedfor engaging said continuous annular surface deformation forming saidstiffening groove for reducing surface contact between said flat end ofsaid spacer means and said rigid member.
 2. A fluid seal as defined inclaim 1 in which said stiffening groove projects axially outwardly awayfrom said spacer means.
 3. A fluid seal as defined in claim 2 in whichsaid spacer means is comprised of a series of spacer tabs, each of saidspacer tabs having a main body portion molded integral with said otherof said resilient members and an integral cylindrical tip portion havinga substantially smaller cross sectional area than said main bodyportion, said tip portion extending axially from said main body portiontoward said radially extending portion of said rigid member and having aflat end for contacting a portion of said surface of said rigid memberon each of two sides of said stiffening groove.